| Diamond is considered an excellent choice for the next generation of semiconductor materials,primarily due to its wide bandgap,high dielectric breakdown field,high carrier mobility,extremely high thermal conductivity,and excellent physical and chemical inertness.The carrier mobility of diamond can reach up to 4500 cm~2/V·s for electrons and 3800 cm~2/V·s for holes.In addition,its electron saturation velocity is1.5×10~7 cm/s,and the hole saturation velocity is 1.1×10~7 cm/s.Appropriate doping and surface treatment can make diamond semiconducting,so that it becomes a semiconductor material with excellent physical and chemical properties.Especially in high-temperature semiconductors and extreme environment applications,diamond has a wide range of promising prospects.The single-crystal diamonds grown using the chemical vapor deposition method possess properties identical to those of naturally occurring granular diamonds and high-pressure synthetic diamonds.This deposition method overcomes the size limitations of natural and high-pressure synthetic diamond production,making it possible to obtain single-crystal diamonds with suitable dimensions and superior quality.However,defects in the growth process of single-crystal diamonds severely restrict the development of commercial diamond electronic products.The growth quality of single crystal diamonds is limited by the substrate’s crystal lattice structure,making it prone to lattice defects such as dislocations and grain boundaries on lower quality substrates.In order to effectively reduce the inherited defects within the lattice,lateral epitaxial growth technology plays a crucial role in the high-quality growth of single crystals.This technique involves growing epitaxial layers laterally on the existing substrate surface,aligning the lattice structure of the epitaxial layer more closely with the substrate.This growth pattern initiates from the surface and gradually extends upwards,thereby decreasing the defect density in the growth direction of the crystal.Lateral epitaxy technology can reduce the defect density on the crystal surface and,as the growth progresses,enclose and eliminate these surface defects.Through this technique,significant improvements in crystal growth quality can be achieved by eliminating lattice defects,providing a flat surface,controlling defect diffusion,and reducing surface defect density.This is of great importance for the fabrication of high-quality semiconductor devices and other optoelectronic applications.To address issues such as the inherited effects of dislocations during single crystal growth,an optimized growth mode using the lateral epitaxy mechanism has been developed,with the following specific innovations:(1)Through systematic experiments and analysis of different substrate holders,growth parameters,and gas compositions,we can explore in depth the growth quality,morphology,and growth kinetics of single crystal diamond,the genetic effect of dislocation on diamond surface is reduced from the perspective of secondary growth.(2)By employing a novel,simple,and cost-effective technique called metal-assisted etching and secondary growth,it is possible to reduce the dislocation density of single crystal diamond.(3)The growth mechanism under different cutting geometries has been analyzed,and after two laser cutting operations,it has been verified that the lateral epitaxy mechanism can improve the quality of the crystal,t is proved that the surface dislocation of diamond is greatly reduced under the control of lateral epitaxy mechanism,and the quality of epitaxy film is significantly improved by changing the growth parameters.(4)Diamond with high quality and low error density can be widely used as a device,the impact of the(100)crystal plane PN junction inclined plane structure on the electrical performance of Schottky barrier diodes(SBD)has been simulated using Silvaco software,combining the junction terminal extension with the inclined plane structure and the parameters of the corresponding structure have been optimized. |
PDF Full Text Request